-
E-mail
shkaizheng@163.com
-
Phone
13391060841
-
Address
305, Building 2, No. 485 Minqiang Road, Songjiang District, Shanghai
Shanghai Kairuo Instrument Co., Ltd
Briefly describe the common problems and corresponding solutions of high-pressure stainless steel crucibles
Date: 2025-09-19Read: 0
High pressure stainless steel crucibles are widely used in material synthesis, geological sample processing, environmental testing, and nuclear industry as products for laboratory high-temperature and high-pressure reactions, digestion, melting, and other operations. Its characteristics of pressure resistance, corrosion resistance, and high temperature resistance enable it to operate safely at pressures of several megapascals and temperatures of hundreds of degrees Celsius. However, long-term use under harsh working conditions often results in sealing failure, corrosion perforation, deformation and jamming of high-pressure stainless steel crucibles. Mastering scientific diagnosis and efficient solutions is the key to ensuring safety and reliability.
1. Poor sealing leads to leakage
Problem manifestation: During the heating or pressurization process, steam or liquid overflows from the gap of the cover.
Reasons and Countermeasures:
Aging of sealing ring: O-type silicone or fluororubber rings are prone to hardening and cracking due to long-term heating, and need to be regularly inspected and replaced every 6-12 months;
Untightened threads: The threads of the lid and kettle body are not tightened, and a torque wrench should be used to evenly lock them with standard torque (to avoid unilateral force);
Sealing surface damage: Check whether there are scratches or residual crystals on the inner surface of the kettle mouth and lid, gently wipe with a soft cloth dipped in alcohol, and strictly prohibit scraping with hard objects.
2. The kettle body or lid is difficult to open
Problem manifestation: Unable to unscrew the lid after the reaction is complete.
Reasons and Countermeasures:
Insufficient cooling: There is still residual pressure inside, and it must be operated after the temperature drops to room temperature and the pressure returns to zero;
Thread biting: Metal expansion at high temperatures causes "cold welding" of threads, which can be loosened by gently tapping the side vibration or slowly applying force with a special wrench;
Preventive measures: Apply a small amount of high-temperature grease (such as molybdenum disulfide) to the thread before each use, but avoid contaminating the sealing ring.
3. Internal wall corrosion or pitting perforation
Problem manifestation: There are spots, pits, and even leakage on the inner wall.
Reasons and Countermeasures:
Incompatible medium: Strong oxidizing acids and halide ions can corrode stainless steel, and a crucible lined with Hastelloy, titanium, or polytetrafluoroethylene should be selected;
Over temperature use: exceeding the material's tolerance temperature (such as 304 stainless steel ≤ 800 ℃, 316L ≤ 900 ℃), resulting in intergranular corrosion;
Improper cleaning: Residual strong acid was not neutralized and cleaned in a timely manner. It is recommended to rinse immediately with deionized water after the reaction and soak in dilute alkali solution if necessary.
4. Deformation or bulging
Problem manifestation: The side wall or bottom of the kettle body protrudes outward.
Reasons and Countermeasures:
Overpressure operation: If the pressure exceeds the design pressure (such as 3MPa, 5MPa), it is strictly prohibited to increase the reaction parameters without authorization;
Local overheating: Direct open flame heating causes uneven heating, and a muffle furnace, oil bath, or electric heating sleeve should be used for uniform heating;
Once deformation is detected, stop using immediately to prevent the risk of explosion.
5. The temperature sensor socket is blocked
Problem manifestation: Unable to insert thermocouple or inaccurate temperature measurement.
Reasons and Countermeasures:
If the reactants splash and solidify, they can be carefully cleared with a fine metal wire;
Avoid covering the temperature measuring hole when using viscous materials;
Regularly check the patency of the ducts.
6. Bottom magnet detachment (with stirring type)
Problem manifestation: The mixing function is malfunctioning.
Reasons and Countermeasures:
Welding point fatigue or corrosion fracture, requiring return to the factory for repair;
Avoid severe collisions or excessive stirring.